Speed regulating apparatus for use with an internal combustion engine



June 18,1957 6. w. CORNELIUS 2,796,055

SPEED REGULATING APPARATUS F OR USE WITH AN INTERNAL COMBUSTION ENGINE 3 Sheets-Sheet 1 Filed March 5, 1954 INVENTOR. .650/265 14/ CORNELIUS- ATT RNEY June 18, 1957 e. w. CORNELIUS 2,796,055

SPEED REGULATING APPARATUS FOR USE WITH AN INTERNAL COMBUSTION ENGINE 3 Sheets-Sheet 2 Filed March 5, 1954 INVENTOR. .6EOR6E MK CORNELIQS.

BY 4M 1. My.

ATTORNE Y June 18, 1957 e. w. CORNELIUS 2,

SPEED REGULATING APPARATUS FOR USE WITH AN INTERNAL COMBUSTION ENGINE 3 Sheets-Sheet 3 Filed March 5, 1954 lllllll INVENTOR. GEORGE W CORNELIUS- rnmsv United SPEED REGULATING APPARATUS FOR USE WITH AN INTERNAL COMBUSTION ENGINE George W. Cornelius, Covina, Calif.

Application March 5, 1954, Serial No. 414,448

12 Claims. (Cl. 123-103) satisfactory in operation, especially where the engine speed must be very accurately maintained within close limits, e. g., where the engine is utilized to drive an electric generator. Under such conditions, the engine generally tends to hunt, first rotating at too great a speed and then suddenly dropping to a too-low speed. The conventional speed-regulating apparatus is, moreover, difiicult to install and requires frequent servicing. Additionally, the conventional speed-regulating apparatus requires a troublesome belt and pulley arrangement for transferring power from the engine thereto, which transfer involves a decided power loss.

It is a major object of the present invention to provide a novel improved speed-regulating apparatus for use with an internal combustion engine.

Another object of the invention is to provide apparatus of this nature which will accurately maintain the speed of an engine between narrow predetermined limits even though the work load of the engine varies between no load and full load.

A further object is to provide speed-regulating ap- V paratus of the aforedescribed nature which utilizes the engines exhaust pressure as a sensing medium for controlling the speed of the engine.

Yet another object of the present invention is to provide apparatus of the aforedescribed nature which is extremely simple of design, has no rapidly moving parts and is rugged of construction, whereby it may have a long, trouble-free service life.

It is a further object to provide speed-regulating apparatus which may be readily installed on an internal combustion engine by even a semi-skilled worker, and which may be adjusted without any special tools or training by such worker.

An additional object of the invention is to provide speed-regulating apparatus especially adapted for use rates Patent O with an internal combustion engine having a constant work load, which apparatus is extremely compact, light in weight and sturdy.

Another object is to provide speed-regulating apparatus which may be installed on existing conventional internal combustion engines without requiring other than Patented June 18, 1957 processes, and hence may be sold at a comparatively low prlce.

Yet another object is to provide speed-regulating apparatus, the utilization of which does not eifect a power loss for the engine whereon it is installed.

These and other objects and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the appended drawings, wherein:

Figure 1 is a side elevational view showing an internal combustion engine whereon is mounted a preferred form of speed-regulating apparatus, embodying the present invention;

Figure 2 is an enlarged, partly sectional, view of said speed-regulating apparatus;

Figure 3 is a fragmentary view of a detail of said speedregulating apparatus;

Figure 4 is a further enlarged central vertical sec tional view of a modification of said speed-regulating apparatus;

Figure 5 is a perspective view, showing another internal combustion engine whereon is mounted a special form of speed-regulating apparatus embodying the present invention;

Figure 6 is an enlarged central vertical sectional view of a major unit of said special form of speed-regulating apparatus; and

Figure 7 is an enlaarged central vertical sectional view of an alternate form of speed-regulating apparatus which may be utilized in conjunction with the engine shown in Figure 5.

General arrangement Referring to the drawings, and particularly to Figure 1 thereof, there is shown a conventional internal combustion engine E mounted on a base 20, which engine mounts a carburetor 22 upon an intake manifold 24. The carburetor 22 includes a throttle arm 26. An exhaust manifold 28 is disposed below the intake manifold 24 and is in communication with an exhaust pipe 30. The speed-regulating apparatus S embodying the present invention is mounted in the vicinity of the carburetor 22 and the intake and exhaust manifolds, and includes an actuating housing A and a control housing C. A rod 32 mounted for reciprocal movement relative to the actuating housing A is connected to the lower end of the throttle arm 26 by a link 34 for controlling the action thereof. A manual overcontrol device for the throttle arm 26 is likewise provided in the form of a cable 36 shown attached to the upper end thereof.

Construction of Figures 2 and 3 More particularly, referring to Figures 2 and 3, the throttle arm 26 is rigidly secured to a pivot pin 38 which is j-ournaled by the side walls of the carburetor throat cylinder 40. A throttle valve 42 is afiixed to the pivot.

arrangement is conventional internal combustion engine practice. Actuator housing A The actuating housing A defines a chamber 44 wherein is mounted a presure-responsive wall 48 that takes the form of a flexible metallic diaphragm. The mid-portion of this diaphragm 46 is rigidly afiixed to the endof the rod 32 opposite the link 34 by a keeper 47. Hence, movement of the diaphragm 46 will elfect concurrent movement of the throttle arm 26 and the throttle valve 42,

The actuating housing A preferably consists of two sections, designated 48 and 50 respectively, that are rigidly joined by a plurality of bolts 52. Section 48 includes a guide collar 54 which slidably. supports the rod 32 for. reciprocal movement toward and away from the carburetor 22. An air vent 5.5 is also formed in section 48. Section 50 is formedv with a cylindricalspring enclosure. 56 aligned with and coaxial to the chamber 44. This spring enclosure 56 is formed with internal. threads 58 for threadably engaging the complementary threads 60 of a closure member 62. This closure member 62 is formed with a bore 64 wherein is disposed a set screw 66 that includes a spring backing element 68. The spring backing element 68 may be formed with threads70 that are engaged with internal threads 58. A lock nut 72 is mounted outwardly of closure member 62. An O-ring 74 and a resilient washer 75 may be provided for sealing the bore 64 and the outer end of the spring enclosure 56, respectively. A helical compressing spring 76 is interposed between the spring backing element 68 and the rod keeper 47 so as to normally bias the rod toward the carburetor 22. In this manner, the throttle valve 42 will normally be urged toward an open position as indicated in Figure 2. The effective length of the spring 76 may be adjusted by means of the set screw 66.

One side of the actuating housing section 50 is formed with a treaded bore 80 adapted to receive an elbow 82. This elbow 82 is connected to the upper end of a main conduit 84; the opposite end of this conduit being connected to a fitting 86. The fitting 86 is threaded within a bore 88 which leads to the throat portion 90 of a venturi tube V disposed in the engines exhaust line; the upper end of this tube V being secured to the exhaust manifold 28 by bolt and nut combinations 92. With this arrangement, during operation of the engine E, the vacuum created in the venturi tubes throat 90 will be communicated through main conduit 84 to the left side of the chamber 44. Such vacuum tends to cause the diaphragm 46 to flex toward the left and there-by move the rod 32 to the left, which rod movement in turn closes the throttle valve 42.

Control housing C T he control housing C defines a chamber 94 wherein is mounted a flexible metal diaphragm 96. The mid-portion of this diaphragm is rigidly afiixed to a piston 98 slidably mounted within a bore 100. The piston carries an O-ring 101 for providing a seal with this bore 100. The upper end. of the piston 98 rigidly mounts an upstanding tapered barrier element or needle 102 for reciprocation relative to an orifice 104. The needle carries an O-ring 105 for providing a seal with a guide bore 106 that encompasses its lower portion. An .air vent 107 is formed below the orifice 104. The opposite side of the orifice is in communication with the main conduit 84 by means of an auxiliary conduit 108. T he upper end of the bore 100 is in: communication with the intake manifold 24by means of a length of tubing 1 10. The upper surface of the diaphragm 96 is in communication with the pressure in the exhaust manifold 28 by means of another length of conduit 1 12, while the underside of this diaphragm is in communication with the throat 90 of the venturi tube V by means of yet another length of tubing 114.

As in the case of the actuator housing A, the control housing C consists of two sections, designated 116 and 118, respectively, that are rigidly joined by a plurality of bolts 120. The lower section 118 includes a spring enclosure 120 formed with internal threads 122for threadably engaging a closure member 124. This closure memher 124 is formed with a bore 126 wherein is disposed a set screw 128 that includes a spring backingelement 130'. The springbacking element may include threads engag ablerwith internal threads 122. -O-ring"131 and'a resilient washerq132 may' beprovided for. sealing-the bore 126. and

the lower end of the housing, respectively. A lock nut 133 is mounted outwardly of closure member 124. A helical compression spring 134 is interposed between the spring backing element 130 and the underside of the diaphragm 96 so as to normally bias the diaphragm, piston 98 and needle 102 upwardly. The effective length of the spring 134 may the adjusted by means of the set screw 128.

Operation of Figures 2 and 3 During operation of the engine E, the vacuum created in the venturi tubes throat 9t) and the positive pressure existing within the exhaust manifold 28 tends to flex the diaphragm 96 downwardly. Meanwhile, the intake manifold vacuum tends to draw the piston 98 (and hence the diaphragm) upwardly. The spring 134 likewise biases the diaphragm upwardly. It should be particularly observed that the area of the piston relative to the area of the diaphragm is such that at no-load, constant-speed engine operation, the intake manifold vacuum tends to draw the piston upwardly with substantially the same amount of force that the vacuum created within the throat tends to draw the diaphragm downwardly. Additionally, at a no-load constant-speed engine operating condition the downwardly-acting force exerted upon the upper surface of the diaphragm by the exhaust manifold pressure entering the control housing C through conduit 112 is balanced by the upward force of the spring 134. Hence, at a no-load, constant-speed engine operating condition, the diaphragm will be maintained in its position of Figure 2, in which position the needle 102 blocks the orifice 104 so as to prevent the flow of atmospheric air into the auxiliary conduit 1.08. Inasmuch as no atmospheric pressure may enter the left side of the actuator chamber 44 during no-load, constant-speed engine operation, the diaphragm 46 will be caused to flex to the left during such operation; the rod maintaining the throttle valve 42 in a near-closed position. The exact throttle valve position may be controlled by adjustment of the set screw 66, such adjustment varying the force being exerted by the spring '76. The position of the throttle valve determines the speed of the engine.

As a load is applied to the engine, the intake manifold vacuum decreases, thereby reducing the upward force acting upon the upper surface of the piston 98; the vacuum in the venturi throat 90 increases, thereby increasing the suction being exerted upon the underside of the diaphragm 96; and, the positive pressure within the exhaust manifold increases, thereby increasing the downward force being exerted upon the upper surface of the diaphragm. Accordingly, the diaphragm, piston and needle will be moved downwardly permitting atmospheric pressure to pass through the orifice 104, conduits 108 and 84, and into the actuating chamber 44. This atmospheric pressure reduces the effectiveness ofthe vacuum created by the venturi throat 90 and transmitted to the chamber by the main conduit 84. Accordingly, the spring 76 is free to urge the diaphragm (and hence the rod 32) to the right so as to open the throttle valve 42 in direct relation to the increased load applied to the engine.

In order to demonstrate the relationship between the intake manifold vacuum, the venturi throat vacuum and the exhaust manifold pressure as the engine load is increased while its speed remains constant, there appears below a chart representing an actual test of an engine equipped with speed-regulating apparatus of the type disclosed herein. The engine tested was coupled to an electric generator, the watt output of which was increased to load the engine. The intake manifold vacuum was measured ininches of mercury, and the exhaust vacuum and manifold pressures were measured in inches of water. The engine speed remained at 1800 R. P. M.

. 7 equal the force of the exhaustgas pressure tending to close the needle valve; such pressure acting against the diaphragm 168. The air-fuel ratio so established will thereafter remain substantially constant even though the engine is kept in operation through a progressive rise in altitude. During such altitude gain, the exhaust gas pressure falls off due to rarefied air conditions. However, as this occurs, the spring 176' will move the needle valve to a more fully opened position so as to automatically meter additional fuel to the engine. Such additional fuel allows the engine to maintain its original constant-speed and constant-load.

It will be apparent that either of the speed-regulating apparatus R and R are adapted for use in controlling the ratio of air-to-fuel rather than fuel-to-air. This may be accomplished by placing a restricting means such as a throttle valve in the engines intake tube 156, and controlling the position of such valve by either of these speedregulating apparatus. Alternately, these apparatus may be utilized to control both the fuel-to-air ratio and the.

air-to-fuel ratio.

While there have been shown and described hereinbefore certain embodiments of the present invention, it will be apparent that various changes and modifications thereof may be made without departing from the spirit of the invention and the scope of the following claims.

I claim:

1. Speed regulating apparatus for use with an internal combustion engine, said engine having valve means for varying the flow of fuel thereto, said engine also having an exhaust line, comprising: a chamber; a flexible diaphram extending across said chamber; means connecting said diaphram to said valve means; spring means normally urging said valve means toward an open position; and, conduit means for connecting said chamber with said exhaust line whereby pressure created therein during operation of said engine will be communicated to one side of said diaphram so as to at least partially ofiset the force of said spring means.

2. Speed regulating apparatus for use with an internal combustion engine, said engine having valve means for varying the flow of fuel thereto, said engine also having an exhaust line, comprising: a chamber; a pressure-responsive wall in said chamber, one side of said wall being exposed to the atmosphere; means operatively connecting said wall and said valve means; biasing means normally urging said valve means toward an open position; and, conduit means for connecting the opposite side of said wall to said exhaust line whereby pressure created therein during operation of said engine will tend to oppose the force exerted by said biasing means.

3. Speed regulating apparatus for use-with an internal combustion engine, said engine having valve means for varying the flow of fuel thereto, said engine also having an exhaust line, comprising: a chamber; a flexible diaphram extending across said chamber, one side of said diaphram being exposed to the'atmosphere; rod means operatively connecting said diaphram and said valve means; spring means acting upon said rod means to normally bias said valve'means toward an open position; and, conduit means for connecting said chamber with said exhaust line whereby pressure created therein during operation of said engine will be communicated to the opposite side of said diaphram so as to at least partially olfset the force of said spring means.

4. Speed regulating apparatus for use with an internal combustion engine, said engine having valve means for varying the how of fuel thereto, said engine also having an exhaust line wherein is disposed venturi means having a throat, comprising: a chamber; apressure-responsive wall in said chamber; biasingmeans tending to move said valve means into an open position; means operatively connecting said wall and said valve'means; and, conduit means connecting said chamber with the throat of said venturi whereby negative pressure created thereinduring operation of said engine will be communicated to one H side of said wall so as to at least partially offset the force of said biasing means.

5. Speed regulating apparatus for use with an internal combustion engine, said engine having valve means for varying the flow of fuel thereto, said engine also having :an exhaust line wherein is disposed venturi means having a throat, comprising: a chamber; a pressure-responsive wall in said chamber, one side of said wall being exposed to atmospheric pressure; means operatively connecting said wall and said valve means; biasing means normally urging said valve means toward an open position; conduit means for connecting said chamber to the throat of said venturi so as to expose the opposite side of said wall to the negative pre-ssurecreated in said throatduring operation of said engine; a second chamber; a second pressureresponsive wall in said second chamber, one side of said wall being in communication with said throat and'the opposite'side thereof being in communication with said exhaust line at one side of said venturi; a piston coaxially mounted by saidsecond wall, said piston being slidably disposed in a bore that forms an axial continuation of said second chamber, and the end of said bore remote from said second Wall being in communication with the intake manifold pressure of said engine; an orifice having one of its sides exposed to the atmosphere and the other side in communication with said conduit means; and, a tapered barrier element mounted by said piston for reciprocal movement within said orifice.

6-. Speed regulating apparatus for use with an internal combustion engine, said engine having valve means for I varying the flow of fuel thereto, said engine also having an exhaustline wherein" is disposed venturi means having a throat, comprising: a'chamber; a pressure-responsive wall in said chamber, one side of said wall being exposed to atmospheric pressure; means operatively connecting said wall and said valve means; biasing means normally urging said valve means toward an open position; conduit means for connecting said chamber to the throat of said venturi so as to expose the opposite side of said wall to the negative pressure created in said throat during operation of said engine; a second chamber that includesa coaxial bore portion at one of its ends; a second pressure-responsive wall in said second chamber, one side of said wall being in communication with said throat and the opposite side thereof being in communication with said exhaust line at one side of said venturi; a piston coaxially mounted by said second wall for reciprocal movement within said bore, the end of said bore remote from said second wall being in communication with the intake manifold pressure of said engine, and the area of said piston relative to that of said second wall being such that at no-load, constant-speed operation of said engine the oppositelyacting forces applied to said piston and said second wall will be substantially equal; second biasing means for urging said second wall toward said bore, the strength of said biasing means at no-load, constant-speed operation of said engine being substantially equal to the oppositelyacting force being exerted upon said second wall by the pressure-existing in said exhaust line; an orifice having one of its sides exposed to the atmosphere and the other side in communication with said conduit means; and, a tapered barrier element mounted by said piston for reciprocal movement within said orifice.

7. Speed regulating apparatus for use with an inter- I nal combustion engine, said engine having valve means for varying the flow of fuel thereto, said engine also raving an exhaust line wherein is disposed venturi means having a throat, comprising: a chamber; a flexible diaphragm extending across said chamber; means operatively connecting said diaphragm to said valve means; spring means normally urging said valve means toward an open position; conduit means for connecting said chamber to the throat of said venturi soas to expose the opposite-side of said wall to the negative pressure created 7 It will be noted by a study of the above chart that the three pressures vary in direct relationship to the load being applied to the engine when the correct adjustments are made to establish the no-load speed at the desired value. It should also be noted that the rate of opening of the throttle valve 42 may be varied from one engine to another either by varying the relative areas of the piston 98 and the diaphragm 96, or by the use of an air bleed at the upper end of the bore 100, or below the diaphragm 96, as the situation may require.

Construction of Figure 4 Referring now to Figure 4, there is shown a modified form of control housing C. This control housing C is generally similar to the aforedescribed control housing C, having a flexible metal diaphragm 96, which rigidly mounts a piston 98 slidably mounted within a bore 100'. This piston 98 mounts a tapered needle 102 for controlling the amount of atmospheric air entering the auxiliary conduit 108 through orifice 104. The upper end of the bore 100 is in communication with the engines intake manifold by means of a length of tubing 110. The upper surface of the diaphragm 96 is in communication with the pressure in the engines exhaust manifold by a conduit 112'. The underside of this diaphragm is not connected to the throat of the venturi tube, however, as in the case of the control chamber C of Figure 2, but instead, it is exposed to atmospheric pressure by means of a restricting orifice 140. It should be noted that the diaphragm 96 is not spring-urged upwardly in the modified control housing C.

Operation of Figure 4 In operation, at idling and at no-load, constant-speed engine operating conditions, the intake manifold pressures will exert greater suction or upward force upon the upper surface of the piston 98 than the downwardly acting force exerted by the exhaust pressure upon the upper surface of the diaphragm )6. Hence, the needle 102 will block 011 any flow of air through the orifice 104. The restricting orifice 140 restrains oscillation of the diaphram 96 due to inpulses from the intake and exhaust manifolds. As the engine load is increased, the intake manifold vacuum decreases while the exhaust pressure increasess (see above chart). Accordingly, the diaphram 96', piston 98', and needle 102 will be moved downwardly permitting atmospheric pressure to pass through the orifice 104 and auxiliary conduit 108. Such atmospheric pressure reduces the effectiveness of the vacuum existing in the chamber 4 of the actuator housing A.

It should be especially observed that the utilization of the venturi tube V in the engines exhaust line smooths out or tunes the exhaust gas surges. The smoothing out of such surges appreciably reduces the back pressure of exhaust gases and hence contributes to the engines efiiciency.

Construction 09 Figures and 6 Referring now to Figure 5, there is shown a conventional two-cycle engine T, whereon is mounted another form of speed-regulating apparatus R embodying the pres ent invention. This engine T is especially adapted for use under constant-speed, constant-load conditions at various altitudes. The engine T includes an exhaust pipe wherein is disposed a venturi section 152 that includes a throat portion 154. Liquid fuel enters the air intake tube 156 of the engine through a fuel line 158.- The amount of fuel entering tube 156 is controlled by a needle valve 160, which needle valve is mounted for axial movement relative to a regulating orifice 162.

As shown in Figure 6, the speed-regulating appa= ratus R includes a two-piece housing 164 which defines a chamber 166 wherein is mounted a pressure-responsive wall or diaphram 168. The mid-portion of the diaphragm 168 rigidly mounts the end of the needle valve opposite the regulating orifice 162. An adjusting rod 170 is threadably mounted by the diaphragm 168 so as to form an axial continuation of the needle valve 160. The end of the adjusting rod 170 opposite the diaphragm is threadably secured to a nut element 172, the underside of which abuts a spring retaining washer 174. A helical compression spring 176 is interposed between the underside of washer 174 and a radially inwardly extending lip 178 formed on the housing 164. A closure member 180 is threadably carried by the housing, which closure member is removable so as to permit adjustment of the effective length of the spring 176. With this arrangement, the spring 176 normally biases the needle valve 160 out of the regulating orifice 162, i. e., towards an open position.

The side of the diaphragm 168 opposite the spring 176 is connected to the throat portion 154 of the venturi 152 by a conduit 182. The opposite side of the diaphragm is in communication with the atmosphere by means of a vent hole 184. An O-ring 186 carried by the needle valve 160 seals the bore 188 between the chamber 166 and fuel passage 190.

Operation of Figures 5 and 6 In operation, with the engine T operating at constantspeed and constant-load, the force of the spring 176 tending to open the needle valve 160 may be adjusted to equal the force of the exhaust gas vacuum tending to close the needle valve; such vacuum acting against the diaphragm 168. The air-fuel ratio so established will thereafter remain substantially constant even though the engine T is kept in operation through a progressive rise in altitude. During such rise in altitude, the exhaust gas vacuum falls off due to rarefied air conditions. However, as this occurs, the spring 176 will move the needle valve to a more fully opened position, so as to automatically meter additional fuel to the engine. Such additional fuel will allow the engine to maintain its original constant-speed and constant-load.

Construction of Figure 7 Referring now to Figure 7, there is shown an alternate form of speed-regulating apparatus R, which may be utilized with the two-cycle engine T in place of the speed-regulating apparatus R described hereinbefore. This apparatus R is substantially similar to apparatus R, except that an air vent 200 is formed in the housing 164 at the side of the diaphragm 168 opposite the spring 176, and the other side of the diaphragm 168' is in com munication with the exhaust pipe (not shown) of the engine by means of a conduit 202. It should be particularly observed that such exhaust pipe is not formed with a venturi section in this case, but instead positive exhaust gas pressure is adapted to enter chamber 166 through the conduit 202.

Operation of Figure 7 In operation, with the engine T operating at constantspeed and constant-load, the force of the spring 176 tending to open the needle valve 160 may be adjusted to in said throat during operation of said engine; a second chamber that includes a coaxial bore portion at one of its ends; a second flexible diaphragm extending across said second chamber, one side of said diaphragm being in communication with said throat and the opposite side thereof being in communication with said exhaust line at one side of said venturi; a piston coaxially mounted by said second diaphragm for reciprocal movement within said bore, the end of said bore remote from said diaphragm being in communication with the intake manifold of said engine; an orifice having one of its sides exposed to the atmosphere and the other side in communication with said conduit means; and, a tapered barrier element mounted by said piston for reciprocal movement within said orifice.

8. Speed regulating apparatus for use with an internal combustion engine, said engine having valve means for varying the flow of fuel thereto, said engine also having an exhaust line wherein is disposed venturi means having a throat, comprising: a chamber; a flexible diaphragm extending across said chamber; means operatively connecting said diaphragm to said valve means; spring means normally urging said valve means toward an open position; conduit means for connecting said chamber to the throat of said venturi so as to expose the opposite side of said wall to the negative pressure created in said throat during operation of said engine; a second chamber that includes a coaxial bore portion at one of its ends; a second flexible diaphragm extending across said second chamber, one side of said diaphragm being in communication with said throat and the opposite side thereof being in communication with said exhaust line at one side of said venturi; second spring means normally urging said second wall toward said bore, the strength of said spring means at no-load, constant-speed operation of said engine being substantially equal to the oppositelyacting force being exerted upon said second diaphragm by the pressure from said exhaust line; a piston coaxially mounted by said second diaphragm for reciprocal movement within said bore, the end of said bore remote from said diaphragm being in communication with the intake manifold of said engine; and the area of said piston relative to that of said second diaphragm being such that at no-load, constant-speed operation of said engine the oppositely-acting forces applied to said piston and to said second diaphragm will be substantially balanced; an orifice having one of its sides exposed to the atmosphere and the other side in communication with said conduit means; and, a tapered barrier element mounted by said piston for reciprocal movement within said orifice.

9. Speed regulating apparatus for use with an internal combustion engine, said engine having valve means for varying the flow of fuel thereto, said engine also having an exhaust line wherein is disposed venturi means having a throat, comprising: an actuator housing defining a coaxial chamber and spring enclosure; a chamber; a flexible diaphragm extending across said chamber; means operatively connecting said diaphragm to said valve means; rod means operatively connecting said diaphragm and said valve means; a closure for the end of said spring enclosure remote from said diaphragm; a helical compression spring in said enclosure and chamber that acts upon said rod means so as to normally bias said valve means toward an open position; conduit means for connecting said chamber with the throat of said venturi whereby negative pressure created therein during operation of said engine will be communicated to the opposite side of said diaphragm so as to at least partially ofiset the force of said spring; a control housing defining a chamber, a coaxial bore at one end of said chamber and a coaxial spring enclosure at the opposite end thereof; a second flexible diaphragm dividing the latter chamber; means for connecting the end of said bore remote from said diaphragm to the intake manifold of said engine; a coaxial piston rigidly mounted by said diaphragm for reciprocal movement within said bore; a second helical compression spring in the enclosure and chamber of said central housing for biasing said diaphragm toward said bore; means for connecting the side of said chamber adjacent said bore with said exhaust line at one side of said venturi; means for connecting the opposite side of said chamber with the throat of said venturi; an orifice formed in said control housing having one of its sides exposed to the atmosphere and its other side in communication with said conduit means; and, a tapered needle mounted by said piston for reciprocal movement within said orifice.

10. Speed regulating apparatus for use with an internal combustion engine that is adapted to operate under constant-speed and constant-load conditions at various altitudes, said engine having a needle valve for controlling the flow of fuel thereto, said engine likewise having an exhaust line comprising: a chamber; a flexible diaphragm extending across said chamber, one side of said diaphragm being exposed to the atmosphere; means connecting said diaphragm and said needle valve; spring means constantly biasing said needle va=lve toward an open position; and conduit means for connecting said chamber with said exhaust line whereby pressure created therein during operation of said engine will be communicated to the opposite side of said diaphragm so as to at least partially offset the force of said spring means.

11. Speed regulating apparatus for use with an internal combustion engine that is adapted to operate under constant-speed and constant-load conditions at various altitudes, said engine having a needle valve for controlling the flow of fuel thereto; said engine likewise having an exhaust line comprising: a housing defining a chamber; a flexible diaphragm extending across said chamber and having its midportion secured to said needle valve; a helical compression spring interposed between said diaphragm and said housing for normally biasing said needle valve toward an open position; an adjusting rod interposed between said diaphragm and said housing for controlling the force exerted by said spring; a vent formed in said housing placing one side of said diaphragm in communication with the atmosphere; and conduit means connecting the opposite side of said diaphragm with said exhaust line whereby pressure created therein during operation of said engine will act against said diaphragm so as to at least partially oifset the force of said spring.

12. Speed regulating apparatus for use with an internal combustion engine, said engine having valve means for varying the flow of fuel thereto, said engine also having an exhaust line wherein is disposed venturi means having a throat, comprising: a chamber; a diaphragm disposed in said chamber, one side of said diaphragm being exposed to atmospheric pressure; spring means normally urging said valve means towards an open position wherein a maximum amount of fuel will be admitted to said engine; and conduit means for connecting said chamber with the throat of said venturi whereby negative pressure created therein during operation of said engine will be communicated to the opposite side of said diaphragm so as to at least partially offset the force of said biasing means.

References Cited in the file of this patent UNITED STATES PATENTS 1,429,795 Strom Sept. 19, 1922 2,356,679 Mallory Aug. 22, 1944 2,374,411 Camner Apr. 24, 1945 2,470,366 Ostling May 17, 1949 2,505,292 Mallory Apr. 25, 1950 

